What's your obsession with album charts? That was never the original point. The original point was that Vivian Campbell was more famous than Adrian Smith in the 80s, and thus not a logical choice for a guitarist who would not outshine Phil Collen. Album sales are only part of that fame. Nor are they even the best measure of fame or reputation, unless you're willing to concede that any artist who outsells Maiden is more famous and respected, which sounds clearly ridiculous to me.
I have no obsession with the album chart...other than correcting any suggestion that Dio had more success than Maiden - I am trusting that you have now accepted this.
And I never mentioned anything about Vivian outshining Phil Collen, did I? I said I suspected that Def Leppard would not have chosen Adrian as a replacement for Steve Clarke because he would not have accepted being a subordinate to Phil. Adrian, after all, was a guitarist in a band that had produced a string of major hit albums (platinum and Top 20 in the USA, number 1s in the UK, Top Ten hits across Europe).
In contrast, at the time that Vivian joined Def Leppard, he was in a band called Shadow King (zero success) and had prior to that been on one tour with Whitesnake and recorded just one song with them (not, as you claimed 'Here I Go Again', but the rather less famous 'Give Me All Your Love 1988 version'.)
And, yes, before that he was with Dio - where he had some success in the USA with 3 albums (but certainly not more than what Maiden enjoyed and certainly much more limited success outside of the USA than what Maiden achieved).
You have made so many claims as to why Vivian was, in your words, 'way more popular and successful than Adrian' in the 1980s. But your supporting claims are not factually correct and all evidence in terms of radio hits and album sales suggest otherwise. Though, I note your claim that Vivian featured on more magazine covers.
In light of this, I have put forward that Adrain was too successful to be adopted into Def Leppard as he would never have accepted being a subordinate to Phil Collen. In contrast, Vivian, with his 'relative' lack of success, was a better choice for Leppard as he has never challenged Phil Collen's place in the spotlight. This is not to say that Vivian is the lesser guitarist as I think he is incredible. But, he is terribly under utlilisied in Def Leppard with the bulk of the solos in concerts going to Phil with Vivian very much in the background. And Vivian has complained as much, but alas, stays with the band.
I appreciate, you have taken all of the above to be some insult to Vivian and Dio - and clearly you are not happy with this. But it was you who has chosen to make an issue out of all of this, when really, my opening post was more more about Adrian than Vivian.
And now I am done with this discussion as it appears to have lost track.